1 /* 2 i2c Support for Apple SMU Controller 3 4 Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp. 5 <benh@kernel.crashing.org> 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 2 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 */ 18 19 #include <linux/module.h> 20 #include <linux/kernel.h> 21 #include <linux/types.h> 22 #include <linux/i2c.h> 23 #include <linux/device.h> 24 #include <linux/platform_device.h> 25 #include <linux/of_irq.h> 26 #include <asm/prom.h> 27 #include <asm/pmac_low_i2c.h> 28 29 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 30 MODULE_DESCRIPTION("I2C driver for Apple PowerMac"); 31 MODULE_LICENSE("GPL"); 32 33 /* 34 * SMBUS-type transfer entrypoint 35 */ 36 static s32 i2c_powermac_smbus_xfer( struct i2c_adapter* adap, 37 u16 addr, 38 unsigned short flags, 39 char read_write, 40 u8 command, 41 int size, 42 union i2c_smbus_data* data) 43 { 44 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); 45 int rc = 0; 46 int read = (read_write == I2C_SMBUS_READ); 47 int addrdir = (addr << 1) | read; 48 int mode, subsize, len; 49 u32 subaddr; 50 u8 *buf; 51 u8 local[2]; 52 53 if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) { 54 mode = pmac_i2c_mode_std; 55 subsize = 0; 56 subaddr = 0; 57 } else { 58 mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub; 59 subsize = 1; 60 subaddr = command; 61 } 62 63 switch (size) { 64 case I2C_SMBUS_QUICK: 65 buf = NULL; 66 len = 0; 67 break; 68 case I2C_SMBUS_BYTE: 69 case I2C_SMBUS_BYTE_DATA: 70 buf = &data->byte; 71 len = 1; 72 break; 73 case I2C_SMBUS_WORD_DATA: 74 if (!read) { 75 local[0] = data->word & 0xff; 76 local[1] = (data->word >> 8) & 0xff; 77 } 78 buf = local; 79 len = 2; 80 break; 81 82 /* Note that these are broken vs. the expected smbus API where 83 * on reads, the length is actually returned from the function, 84 * but I think the current API makes no sense and I don't want 85 * any driver that I haven't verified for correctness to go 86 * anywhere near a pmac i2c bus anyway ... 87 * 88 * I'm also not completely sure what kind of phases to do between 89 * the actual command and the data (what I am _supposed_ to do that 90 * is). For now, I assume writes are a single stream and reads have 91 * a repeat start/addr phase (but not stop in between) 92 */ 93 case I2C_SMBUS_BLOCK_DATA: 94 buf = data->block; 95 len = data->block[0] + 1; 96 break; 97 case I2C_SMBUS_I2C_BLOCK_DATA: 98 buf = &data->block[1]; 99 len = data->block[0]; 100 break; 101 102 default: 103 return -EINVAL; 104 } 105 106 rc = pmac_i2c_open(bus, 0); 107 if (rc) { 108 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc); 109 return rc; 110 } 111 112 rc = pmac_i2c_setmode(bus, mode); 113 if (rc) { 114 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n", 115 mode, rc); 116 goto bail; 117 } 118 119 rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len); 120 if (rc) { 121 if (rc == -ENXIO) 122 dev_dbg(&adap->dev, 123 "I2C transfer at 0x%02x failed, size %d, " 124 "err %d\n", addrdir >> 1, size, rc); 125 else 126 dev_err(&adap->dev, 127 "I2C transfer at 0x%02x failed, size %d, " 128 "err %d\n", addrdir >> 1, size, rc); 129 goto bail; 130 } 131 132 if (size == I2C_SMBUS_WORD_DATA && read) { 133 data->word = ((u16)local[1]) << 8; 134 data->word |= local[0]; 135 } 136 137 bail: 138 pmac_i2c_close(bus); 139 return rc; 140 } 141 142 /* 143 * Generic i2c master transfer entrypoint. This driver only support single 144 * messages (for "lame i2c" transfers). Anything else should use the smbus 145 * entry point 146 */ 147 static int i2c_powermac_master_xfer( struct i2c_adapter *adap, 148 struct i2c_msg *msgs, 149 int num) 150 { 151 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); 152 int rc = 0; 153 int addrdir; 154 155 if (msgs->flags & I2C_M_TEN) 156 return -EINVAL; 157 addrdir = i2c_8bit_addr_from_msg(msgs); 158 159 rc = pmac_i2c_open(bus, 0); 160 if (rc) { 161 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc); 162 return rc; 163 } 164 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); 165 if (rc) { 166 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n", 167 pmac_i2c_mode_std, rc); 168 goto bail; 169 } 170 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len); 171 if (rc < 0) { 172 if (rc == -ENXIO) 173 dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n", 174 addrdir & 1 ? "read from" : "write to", 175 addrdir >> 1, rc); 176 else 177 dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n", 178 addrdir & 1 ? "read from" : "write to", 179 addrdir >> 1, rc); 180 } 181 bail: 182 pmac_i2c_close(bus); 183 return rc < 0 ? rc : 1; 184 } 185 186 static u32 i2c_powermac_func(struct i2c_adapter * adapter) 187 { 188 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 189 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | 190 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C; 191 } 192 193 /* For now, we only handle smbus */ 194 static const struct i2c_algorithm i2c_powermac_algorithm = { 195 .smbus_xfer = i2c_powermac_smbus_xfer, 196 .master_xfer = i2c_powermac_master_xfer, 197 .functionality = i2c_powermac_func, 198 }; 199 200 static const struct i2c_adapter_quirks i2c_powermac_quirks = { 201 .max_num_msgs = 1, 202 }; 203 204 static int i2c_powermac_remove(struct platform_device *dev) 205 { 206 struct i2c_adapter *adapter = platform_get_drvdata(dev); 207 208 i2c_del_adapter(adapter); 209 memset(adapter, 0, sizeof(*adapter)); 210 211 return 0; 212 } 213 214 static u32 i2c_powermac_get_addr(struct i2c_adapter *adap, 215 struct pmac_i2c_bus *bus, 216 struct device_node *node) 217 { 218 const __be32 *prop; 219 int len; 220 221 /* First check for valid "reg" */ 222 prop = of_get_property(node, "reg", &len); 223 if (prop && (len >= sizeof(int))) 224 return (be32_to_cpup(prop) & 0xff) >> 1; 225 226 /* Then check old-style "i2c-address" */ 227 prop = of_get_property(node, "i2c-address", &len); 228 if (prop && (len >= sizeof(int))) 229 return (be32_to_cpup(prop) & 0xff) >> 1; 230 231 /* Now handle some devices with missing "reg" properties */ 232 if (!strcmp(node->name, "cereal")) 233 return 0x60; 234 else if (!strcmp(node->name, "deq")) 235 return 0x34; 236 237 dev_warn(&adap->dev, "No i2c address for %pOF\n", node); 238 239 return 0xffffffff; 240 } 241 242 static void i2c_powermac_create_one(struct i2c_adapter *adap, 243 const char *type, 244 u32 addr) 245 { 246 struct i2c_board_info info = {}; 247 struct i2c_client *newdev; 248 249 strncpy(info.type, type, sizeof(info.type)); 250 info.addr = addr; 251 newdev = i2c_new_device(adap, &info); 252 if (!newdev) 253 dev_err(&adap->dev, 254 "i2c-powermac: Failure to register missing %s\n", 255 type); 256 } 257 258 static void i2c_powermac_add_missing(struct i2c_adapter *adap, 259 struct pmac_i2c_bus *bus, 260 bool found_onyx) 261 { 262 struct device_node *busnode = pmac_i2c_get_bus_node(bus); 263 int rc; 264 265 /* Check for the onyx audio codec */ 266 #define ONYX_REG_CONTROL 67 267 if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) { 268 union i2c_smbus_data data; 269 270 rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ, 271 ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA, 272 &data); 273 if (rc >= 0) 274 i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46); 275 276 rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ, 277 ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA, 278 &data); 279 if (rc >= 0) 280 i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47); 281 } 282 } 283 284 static bool i2c_powermac_get_type(struct i2c_adapter *adap, 285 struct device_node *node, 286 u32 addr, char *type, int type_size) 287 { 288 char tmp[16]; 289 290 /* Note: we to _NOT_ want the standard 291 * i2c drivers to match with any of our powermac stuff 292 * unless they have been specifically modified to handle 293 * it on a case by case basis. For example, for thermal 294 * control, things like lm75 etc... shall match with their 295 * corresponding windfarm drivers, _NOT_ the generic ones, 296 * so we force a prefix of AAPL, onto the modalias to 297 * make that happen 298 */ 299 300 /* First try proper modalias */ 301 if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) { 302 snprintf(type, type_size, "MAC,%s", tmp); 303 return true; 304 } 305 306 /* Now look for known workarounds */ 307 if (!strcmp(node->name, "deq")) { 308 /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */ 309 if (addr == 0x34) { 310 snprintf(type, type_size, "MAC,tas3001"); 311 return true; 312 } else if (addr == 0x35) { 313 snprintf(type, type_size, "MAC,tas3004"); 314 return true; 315 } 316 } 317 318 dev_err(&adap->dev, "i2c-powermac: modalias failure on %pOF\n", node); 319 return false; 320 } 321 322 static void i2c_powermac_register_devices(struct i2c_adapter *adap, 323 struct pmac_i2c_bus *bus) 324 { 325 struct i2c_client *newdev; 326 struct device_node *node; 327 bool found_onyx = 0; 328 329 /* 330 * In some cases we end up with the via-pmu node itself, in this 331 * case we skip this function completely as the device-tree will 332 * not contain anything useful. 333 */ 334 if (!strcmp(adap->dev.of_node->name, "via-pmu")) 335 return; 336 337 for_each_child_of_node(adap->dev.of_node, node) { 338 struct i2c_board_info info = {}; 339 u32 addr; 340 341 /* Get address & channel */ 342 addr = i2c_powermac_get_addr(adap, bus, node); 343 if (addr == 0xffffffff) 344 continue; 345 346 /* Multibus setup, check channel */ 347 if (!pmac_i2c_match_adapter(node, adap)) 348 continue; 349 350 dev_dbg(&adap->dev, "i2c-powermac: register %pOF\n", node); 351 352 /* 353 * Keep track of some device existence to handle 354 * workarounds later. 355 */ 356 if (of_device_is_compatible(node, "pcm3052")) 357 found_onyx = true; 358 359 /* Make up a modalias */ 360 if (!i2c_powermac_get_type(adap, node, addr, 361 info.type, sizeof(info.type))) { 362 continue; 363 } 364 365 /* Fill out the rest of the info structure */ 366 info.addr = addr; 367 info.irq = irq_of_parse_and_map(node, 0); 368 info.of_node = of_node_get(node); 369 370 newdev = i2c_new_device(adap, &info); 371 if (!newdev) { 372 dev_err(&adap->dev, "i2c-powermac: Failure to register" 373 " %pOF\n", node); 374 of_node_put(node); 375 /* We do not dispose of the interrupt mapping on 376 * purpose. It's not necessary (interrupt cannot be 377 * re-used) and somebody else might have grabbed it 378 * via direct DT lookup so let's not bother 379 */ 380 continue; 381 } 382 } 383 384 /* Additional workarounds */ 385 i2c_powermac_add_missing(adap, bus, found_onyx); 386 } 387 388 static int i2c_powermac_probe(struct platform_device *dev) 389 { 390 struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev); 391 struct device_node *parent = NULL; 392 struct i2c_adapter *adapter; 393 const char *basename; 394 int rc; 395 396 if (bus == NULL) 397 return -EINVAL; 398 adapter = pmac_i2c_get_adapter(bus); 399 400 /* Ok, now we need to make up a name for the interface that will 401 * match what we used to do in the past, that is basically the 402 * controller's parent device node for keywest. PMU didn't have a 403 * naming convention and SMU has a different one 404 */ 405 switch(pmac_i2c_get_type(bus)) { 406 case pmac_i2c_bus_keywest: 407 parent = of_get_parent(pmac_i2c_get_controller(bus)); 408 if (parent == NULL) 409 return -EINVAL; 410 basename = parent->name; 411 break; 412 case pmac_i2c_bus_pmu: 413 basename = "pmu"; 414 break; 415 case pmac_i2c_bus_smu: 416 /* This is not what we used to do but I'm fixing drivers at 417 * the same time as this change 418 */ 419 basename = "smu"; 420 break; 421 default: 422 return -EINVAL; 423 } 424 snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename, 425 pmac_i2c_get_channel(bus)); 426 of_node_put(parent); 427 428 platform_set_drvdata(dev, adapter); 429 adapter->algo = &i2c_powermac_algorithm; 430 adapter->quirks = &i2c_powermac_quirks; 431 i2c_set_adapdata(adapter, bus); 432 adapter->dev.parent = &dev->dev; 433 434 /* Clear of_node to skip automatic registration of i2c child nodes */ 435 adapter->dev.of_node = NULL; 436 rc = i2c_add_adapter(adapter); 437 if (rc) { 438 printk(KERN_ERR "i2c-powermac: Adapter %s registration " 439 "failed\n", adapter->name); 440 memset(adapter, 0, sizeof(*adapter)); 441 return rc; 442 } 443 444 printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name); 445 446 /* Use custom child registration due to Apple device-tree funkyness */ 447 adapter->dev.of_node = dev->dev.of_node; 448 i2c_powermac_register_devices(adapter, bus); 449 450 return 0; 451 } 452 453 static struct platform_driver i2c_powermac_driver = { 454 .probe = i2c_powermac_probe, 455 .remove = i2c_powermac_remove, 456 .driver = { 457 .name = "i2c-powermac", 458 .bus = &platform_bus_type, 459 }, 460 }; 461 462 module_platform_driver(i2c_powermac_driver); 463 464 MODULE_ALIAS("platform:i2c-powermac"); 465